Hi all,
Seeking some advise from the NIssan gurus out there. Someone just offered me a turbo exhaust manifold for the L series engine. He claims it is an HKS unit. It looks to me like a factory manifold with an old HKS blow off valve. I was wondering if it is true and if anyone has any pictures of the complete setup (with surge tank?).

I'm by no means an expert, but that looks like a stock manifold with an adapter on it. Maybe the adapter is made by HKS?

Note exit of stock manifold:




Of course, most of the stock ones I've seen have casting numbers on them too... Which could've been ground off?

Thanks, John. Yeah, the extra attachment to the manifold might be the HKS item. Is it just me or is the turbo flange on the manifold for sale closer to the centre than the standard manifold you posted? The flange to the head also looks different. I guess there were probably many variations of the standard manifold made. Too bad no one has posted any copies of early HKS catalogues featuring L-series parts. Would make a good reference.

Now that you mention it, yes.

Looks like you have a L20et manifold with an HKS adapter.

Hi jncr,
Thanks for the feedback. It is not mine. Still contemplating if it is worth getting. Does this match up with the ultra expensive HKS surge tank? Images of the surge tank show it with its own BOV. What does the flexible hose attached to the manifold do? Cannot seem to get any references online.

That is not a BOV. That is an external wastegate. The flexible pipe is the WG exhaust. Usually vented back into the down pipe.

The HKS surge tank attaches to the Intake side and is not a concern with this setup.

Thanks, Jncr. Valuable info.

Just saw this thread, I was running exactly that setup on my turbo 3.1L motor. I had to fit a heavier spring into the wastegate as it wasn't holding boost but worked okay up to 320rwhp. It puts the turbo in a good place, clears the inlet manifold and engine mount fine.

And there are two types of common turbo manifolds, the one with the flange further forward I have seen fitted to R30 Skylines and C31 Laurels, but I've also seen R30s fitted with the flange further back which is better in my opinion as the turbo might not clear the engine mount as well with the further forward one.

Thanks for the info.